From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F1AF63D2FFB for ; Wed, 8 Apr 2026 14:14:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775657681; cv=none; b=Bo3HvHvIvh054ryAtb1qTXzYzWUrA8e/pbqts58Mx5jVX/BODaQyODFoClObdVtfVr6Cg94vTuwHNVs2e6K11oEsDkaQlJxnhlKXWgLrV5rmcOdRuME0Pq143ffsSM2mC2U54XtZB7kA1efPIchGjCTDYs1ILABRpdIpQlt3NCw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775657681; c=relaxed/simple; bh=4758blXblSGraxxNLUVAoZhJhgiAHLM/ofkX9ZNtkB0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=V07NO9SIaLYw5QZ5SfZ2qmUw79nUSRq1wpkhAgQuiKpAV6L4rlvpQBXvdidQab2OwhHEx5h93mtuQ56vXFcW7LYGxO1HKbWAT7YtgIgAUi0vK3VYBh1KsCN5WHtlnF1K5jnkcU3pU5nKaHJuCr4Em1KdVHZiQ7+fazgmZWtYJq4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=cmplxyhy; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="cmplxyhy" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 29166C19421; Wed, 8 Apr 2026 14:14:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1775657680; bh=4758blXblSGraxxNLUVAoZhJhgiAHLM/ofkX9ZNtkB0=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=cmplxyhycPBF8vYPibwQTrtzSgECpnUii+twBF29DlInFp4TWJ+W+NOsiWVeS/eTc +UhbqSn8Ufvx6rNHfDIhUxHM0z9WhVaxfSiWV21Oy6cO5hkqVANXuFPAPoimjKimVb Ec7aTg2V3/ALm/7G/7McUe8FQ2vVb2gKOwEVR3l2JAKknHVty/UOSB3I7m3pVGo/1i /N4o/TrFBvkFUY96Vl1v4QW833tqNFHbP3pplkwDt8JeBZaGUw+tAT3cFvCKUmAcew YEpTrztVTpXHNDMm0OCmGYYqT2HH1JdwznuwtE1h/6r7g8CAC5bEp7DXW1GYsPbzm/ 3TxrQLHQ4CNFA== Message-ID: <3b7d20c2-a0c7-42c9-b303-1dfd6503cae1@kernel.org> Date: Wed, 8 Apr 2026 16:14:37 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 00/11] mm: thp: always enable mTHP support To: Luiz Capitulino , linux-kernel@vger.kernel.org, linux-mm@kvack.org, baolin.wang@linux.alibaba.com Cc: ryan.roberts@arm.com, akpm@linux-foundation.org, lorenzo.stoakes@oracle.com References: <835725cc-1670-45ae-bf58-593aadec6b88@kernel.org> <8d03a508-5836-4001-8eb8-b216251dc29d@redhat.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 4/2/26 13:56, Luiz Capitulino wrote: > On 2026-04-02 04:25, David Hildenbrand (Arm) wrote: >> On 2/9/26 23:14, Luiz Capitulino wrote: >>> Today, if an architecture implements has_transparent_hugepage() and >>> the CPU >>> lacks support for PMD-sized pages, the THP code disables all THP, >>> including >>> mTHP. In addition, the kernel lacks a well defined API to check for >>> PMD-sized page support. It currently relies on >>> has_transparent_hugepage() >>> and thp_disabled_by_hw(), but they are not well defined and are tied to >>> THP support. >>> >>> This series addresses both issues by introducing a new well defined API >>> to query PMD-sized page support: pgtable_has_pmd_leaves(). Using this >>> new helper, we ensure that mTHP remains enabled even when the >>> architecture or CPU doesn't support PMD-sized pages. >>> >>> Thanks to David Hildenbrand for suggesting this improvement and for >>> providing guidance (all bugs and misconceptions are mine). >>> >>> This applies to v6.19, but I tested it on v6.19-rc8+. >> >> Apologies for the delay Luiz (as told you off-list :) ), I'll try going >> through this soon so we can start queuing this after -rc1. > > Oh, wow, thanks for the support! > > I intended to get back to this series this week to address Baolin's > comments, but I got busy with other things (which is something I may > bring up on upstream but it's not related to this series at all). > Okay, I'll wait for your next posting and prioritize that :) -- Cheers, David